An LCD has the advantages of portability, low power consumption, and low radiation, and has been widely used in various portable information products such as notebooks, personal digital assistants (PDAs), video cameras and the like. Furthermore, the LCD is considered by many to have the potential to completely replace CRT (cathode ray tube) monitors and televisions.
FIG. 7 is essentially an abbreviated circuit diagram of a driving circuit of a typical LCD. The driving circuit 100 includes a number n (where n is a natural number) of gate lines 101 that are parallel to each other and that each extend along a first direction, a number m (where m is also a natural number) of data lines 102 that are parallel to each other and that each extend along a second direction orthogonal to the first direction, a plurality of thin film transistors (TFTs) 106 that function as switching elements, a plurality of pixel electrodes 103, a plurality of common electrodes 105, a gate driving circuit 110, and a data driving circuit 120. The crossed gate lines 101 and data lines 102 define an array of pixel units of the LCD. Each pixel unit includes a respective TFT 106, a respective pixel electrode 103, and a respective common electrode 105. The TFT 106 is provided in the vicinity of a respective point of intersection of the gate lines 101 and the data lines 102. The gate driving circuit 110 is used to drive the gate lines 101. The data driving circuit 120 is used to drive the data lines 102.
FIG. 8 is an equivalent circuit diagram relating to the driving circuit 100 at any one of the pixel units. A gate electrode 1062, a source electrode 1064, and a drain electrode 1066 of the TFT 106 are connected to a corresponding gate line 101, a corresponding data line 102, and a corresponding pixel electrode 103 respectively. Liquid crystal material sandwiched between the pixel electrode 103 on a first substrate (not shown) and the common electrode 105 on a second substrate (not shown) is represented as a liquid crystal capacitor Clc. Csd is a parasitic capacitor formed between the source electrode 1064 and the drain electrode 1066 of the TFT 106.
The data line 102 has an essential resistance R, which associated with the parasitic capacitor Csd forms an RC (resistance-capacitance) delay circuit. The RC delay circuit distorts a data signal applied to the data line 102. A distortion of the data signal is determined by the essential resistance R and a capacitance of the parasitic capacitor Csd.
Referring also to FIG. 9, this is a waveform diagram showing distortion of a data signal applied to any one of the data lines 102. Vd1 shows a waveform of the data signal when the data signal is adjacent the data driving circuit 120. Vd2 shows a waveform of the data signal when the data signal is far from the data driving circuit 120. The distortion of the data signal becomes more pronounced with increasing distance from the data driving circuit 120. If the LCD is large, the data line 102 is correspondingly long. Therefore the problem of data signal distortion may be significant, and the display performance of the LCD is liable to be impaired.
What is needed, therefore, is an LCD that can overcome the above-described deficiencies.